"""
* This file is part of PYSLAM
*
* Copyright (C) 2016-present Luigi Freda <luigi dot freda at gmail dot com>
*
* PYSLAM is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* PYSLAM is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with PYSLAM. If not, see <http://www.gnu.org/licenses/>.
"""

import cv2
from .moving_average import MovingAverage
from .utils_sys import Printer

# timer_print = print
timer_print = Printer.cyan


class Timer:
    def __init__(self, name="", is_verbose=False):
        self._name = name
        self._is_verbose = is_verbose
        self._is_paused = False
        self._start_time = None
        self._accumulated = 0
        self._elapsed = 0
        self.start()

    def start(self):
        self._accumulated = 0
        self._start_time = cv2.getTickCount()

    @property
    def start_time(self):
        return self._start_time

    @property
    def last_elapsed(self):
        return self._elapsed

    def pause(self):
        now_time = cv2.getTickCount()
        self._accumulated += (now_time - self._start_time) / cv2.getTickFrequency()
        self._is_paused = True

    def resume(self):
        if self._is_paused:  # considered only if paused
            self._start_time = cv2.getTickCount()
            self._is_paused = False

    def elapsed(self):
        if self._is_paused:
            self._elapsed = self._accumulated
        else:
            now = cv2.getTickCount()
            self._elapsed = self._accumulated + (now - self._start_time) / cv2.getTickFrequency()
        if self._is_verbose is True:
            name = self._name
            if self._is_paused:
                name += " [paused]"
            message = "Timer::" + name + " - elapsed: " + str(self._elapsed)
            timer_print(message)
        return self._elapsed


class TimerFps(Timer):
    def __init__(self, name="", average_width=10, is_verbose=False):
        super().__init__(name, is_verbose)
        self.moving_average = MovingAverage(average_width)

    def refresh(self):
        elapsed = self.elapsed()
        self.moving_average.getAverage(elapsed)
        self.start()
        if self._is_verbose is True:
            dT = self.moving_average.getAverage()
            name = self._name
            if self._is_paused:
                name += " [paused]"
            message = "Timer::" + name + " - fps: " + str(1.0 / dT) + ", T: " + str(dT)
            timer_print(message)
